Recent content by Diomarte

A related update on this. Following the Nielsen model, when I decrease the maximum packing fraction of the filler particles in the composite, the calculated thermal conductivity increases. To me, this was surprising, as I expected that a higher packing fraction (of a particle with significantly...

Oh, and if anyone has any idea where I can find the original derivations for the equations in the Lewis-Nielson, or Halping-Tsai equations, I would sincerely appreciate it. I have been using Nielsen's book "Mechanical Properties of Polymers and Composites" for a lot of my research, but Nielsen...

Hi, Sorry for the semi-book here I am working on a project where I am mixing h-BN nanoparticles into a polymer resin to try to tailor the thermal conductivity and dielectric strength of the resulting composite. Admittedly I am not very well versed when it comes to materials science...

Have you considered Boron Nitride?

I do have one last question for you, does [Px, Py] commute? (Do each part of [Pi,Pj] commute?

Never mind, Vela, you're amazing and awesome, and I really appreciate all the help you've given me. You answer just about every question I ask, and for that I thank you. I totally just woke up, and now things are making sense again. I think I need a short break.

Most definitely, but forgive my lack of understanding at 1:00am , but is there a physical explanation, or is this just one of those things that is only mathematical?

"The only operator in Lz that does not commute with x, is Px..." but why?

so I'm left only with -z[y,Py] huh? I've worked it out a few times, and if I remember correctly [y,Pz] clearly vanishes when operating on some form of dummy function, but without actually working it out, can you explain briefly why exactly it vanishes?

Thank you both. I was able to solve that problem, I have moved forward in this problem and am stuck on the [r^2, Lx] portion. I know that the x[x,Lx] + [x,Lx]x = 0 and that I'm left with the y and z terms, but I'm having trouble with those. Do you have any suggestions towards that approach...

Homework Statement For an angular momentum operator ~L =ˆiLx +ˆjˆLy + ˆkˆLz = ˆr × ˆp, prove that [ˆLx, ˆLy] = i\hbarˆLz, [ˆLx, ˆLz] = −i\hbarˆLy, [ˆL2, ˆLx] = 0, [p^{2}, ˆLx] = 0, [r^{2}, ˆLx] = 0, [ˆLx, ˆy] = i\hbarˆz, [ˆLx, ˆpy] = i\hbarˆPz. **Note: I'm really only looking for help for the...

Ok, never mind, I figured out what was going on. Thank you all very much for your help. After following what was going on, I've successfully solved four of my five assignments! I'll post what I did later on tonight when I've got the time, so if other people have a similar question, they have a...

Alright, so I performed the operations and got <x> = 0 and <p> = 0. Two other students I spoke with said that they got <p> = 0 but not <x>. Am I making another mistake here?

"Though it doesn't make a difference." Why do you say this vela? Is it because of the orthogonality and cancellation if you end up multiplying through after the operations?

Meaning have the a+ operator act on the bras and then the a_ operate on the kets?